Genetic aspects of familial amyloidosis with corneal lattice dystrophy and cranial neuropathy.

Abstract

A genetic analysis of familial systemic amyloidosis with lattice corneal dystrophy, facial paresis and nephropathy has been made. The 228 sibships which were at risk of the disease contained 851 sibs who were subdivided as follows: 207 affected, 134 normal, 158 not examined, 138 not diagnosed because they were too young, and 214 dead sibs.The mode of inheritance was found to be autosomal dominant. The sex ratio corresponded to unity after adequate corrections. The corrected average proportion of affected individuals per sib‐ship was 54.4 ± 3.7% by maximum likelihood method.In two cases there was a strong suspicion of homozygosity for the condition. These cases probably have a limited survival, whereas the heterozygous cases have a better prognosis.Two areas were found to have a high prevalence of the disease: Kymenlaakso and South Häme districts in Finland. In the former, this was 1/1,040 among 182,000 inhabitants, whereas in 1860 in the parish Valkeala the prevalence was calculated at 1/155. Today the true prevalence probably lies between these figures.